HP D7171A - NetServer - LPr Manual page 9

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different levels (0, 1, 3, 5, 10, 30 and 50) which allow users to vary the degrees of
performance, availability and flexibility.
I O
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The I
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is independent of both the specified device being controlled and the host operating system
(OS). The I
I/O processing:
System performance degradation caused by I/O interrupts to the CPU (the CPU is not
doing data processing when it is processing I/O requests)
The necessity to create, test, and support unique drivers for every combination of
I/O device and OS on the market
HP was the founding company of the Special Interest Group (I
significant input into the direction of the development effort of the specifications, including
the initial invention, and has been assigned the patent.
The new architecture of I
handle I/O rather than the CPU which offloads low-level interrupts to these processors. The
I O specification also creates a "split driver" model so that the software drivers are portable
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across multiple OSs and host platforms. One portion of the driver runs in the operating
system, the other portion runs in a separate I/O system. The split driver concept will reduce
the number of drivers that must be written. OS vendors will write a single I
for each class of device—such as a disk drive—and the device manufacturers write a
single I
split-driver approach will drive down the cost of software development and support for
I/O devices while increasing their availability across the range of operating systems.
Other benefits that will come as I
reduced CPU utilization, "plug-and-play" flexibility, and a more stable I/O driver platform.
I O is being implemented step-by-step like many technology standards that came before it.
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Operating system vendors began releasing the systems that provide support for I
1998. Hewlett-Packard has launched the HP NetRAID-3Si disk array controller, the first in a
line of HP NetServer products that will support the I
Fibre Channel
Just as I
entire server system, the addition of Fibre Channel connectivity enhances system
performance and availability. Fibre Channel was first offered with HP-UX server storage
and has become widely available with NT-based servers over the last year. There are
currently 3 external disk storage products that can be connected to HP NetServers via
Fibre Channel—the HP Rack Storage/12FC, the HP Model 30/FC and the EMC Symmetrix.
HP also offers connectivity of DLT Backup Libraries to FC via the HP SureStore Fibre
Channel SCSI Bridge.
Fibre Channel connections between server and storage are made using a set of
components similar to those used for IP networking. A Fibre Channel-to-PCI host bus
O (Intelligent Input/Output) specification defines an architecture for intelligent I/O that
O specification has been developed to address two key problem areas in
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O utilizes an approach whereby I/O processors are used to
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O-ready driver for each device, which will work for any OS that supports I
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O capability improves the input/output transfers and the performance of the
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O is fully implemented are improved server efficiency,
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O standard.
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O SIG) and has had a
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O-ready driver
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O. The
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O in early
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